<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script src="../practice_project/js/vue.js"></script>
    <script>
        const root = new Vue({ //=号两边有空格
            // 当然每个公司都有每个公司的规定
            el: '#root' //冒号后面留一个空格
        })
    </script>
</body>

</html>